Secondary battery

Abstract

A technical problem to be solved according to the present disclosure is to provide a secondary battery capable of minimizing contact resistance between a base finish part of an electrode assembly and a can even when a deviation in the winding radius of the electrode assembly occurs, by positioning a swelling tape inside the electrode assembly. To this end, the present disclosure provides a secondary battery including: a cylindrical can, an electrode assembly having a base finish part electrically contacting the cylindrical can; a cap assembly sealing the electrode assembly by blocking the cylindrical can; and a swelling tape positioned inside the base finish part to press the base finish part into the cylindrical can.

1 . A secondary battery comprising:
 a cylindrical can;   an electrode assembly having a base finish part electrically contacting the cylindrical can;   a cap assembly sealing the electrode assembly by blocking the cylindrical can; and   a swelling tape positioned inside the base finish part to press the base finish part to the cylindrical can.   
     
     
         2 . The secondary battery as claimed in  claim 1 , wherein the can includes a bottom portion and a side portion extending from the bottom portion, and the swelling tape presses the base finish part to the side portion. 
     
     
         3 . The secondary battery as claimed in  claim 1 , wherein the electrode assembly includes a first electrode plate, a separator positioned on the first electrode plate, and a second electrode plate positioned on the separator, wherein the first electrode plate, the separator, and the second electrode plate are laminated and wound, and the base finish part is provided by wrapping the outermost periphery of the electrode assembly with the first electrode plate. 
     
     
         4 . The secondary battery as claimed in  claim 3 , wherein the first electrode plate includes a conductive first base having inner and outer surfaces, a coating portion provided by coating a first active material on the inner and outer surfaces of the first base, and a non-coating portion provided by not coating the first active material on the inner and outer surfaces of the first base, and the non-coating portion covers the outermost periphery of the electrode assembly. 
     
     
         5 . The secondary battery as claimed in  claim 4 , wherein the base finish part includes the non-coating portion. 
     
     
         6 . The secondary battery as claimed in  claim 4 , wherein the swelling tape is adhered to an inner surface of the base finish part. 
     
     
         7 . The secondary battery as claimed in  claim 4 , wherein the swelling tape is interposed between the inner surface of the base finish part and the separator. 
     
     
         8 . The secondary battery as claimed in  claim 4 , wherein the first electrode plate further includes a first tab welded to the first base, and the first tab is electrically connected to the cylindrical can. 
     
     
         9 . The secondary battery as claimed in  claim 4 , wherein a length of the swelling tape is 1% to 100% of the length of the non-coating portion. 
     
     
         10 . The secondary battery as claimed in  claim 4 , wherein a winding-turn length of the swelling tape is 0.1-1 turn compared to a winding-turn length of the base finish part. 
     
     
         11 . The secondary battery as claimed in  claim 1 , wherein the swelling tape absorbs an electrolyte to be swollen. 
     
     
         12 . The secondary battery as claimed in  claim 1 , wherein the swelling tape includes an acrylic binder.